When it first became acceptable for women to appear in public in bathing suits, the attire covered up a considerable portion of the body. Swimwear has since evolved to the tight fitting one piece bathing suit and then to the two piece bathing suit. From there swimwear has developed to the bikini with some of the very small ones being referred to as mini or micro bikinis.
These latter types are fine for the average woman to wear when swimming and sunbathing but are not suitable for spring board diving, water skiing, hydrosliding, and the like where the forces of the water are likely to partially or wholly disrobe the wearer thereof.
Also, the bikini types of bathing suits are generally not worn by women that have had midline incisions due to Caesarean Section births, hysterectomies, and the like. To still be able to get a suntan and yet not show their scars in public, two piece bathing suits are usually resorted to which can be folded down when in private. This is not a very acceptable alternative, however, to the woman who wants a genuine bikini suntan.